Standard Clegg Hammer

The 4.5 kg "Standard" Clegg Impact Soil
Tester was the first Clegg Hammer developed by Dr. Baden Clegg in the
1970's. It was initally concieved for basecourse testing but has
turned out to be the "general purpose" Clegg. It is based on the
instrumentation of a "modified proctor" labotratory compaction hammer. The
Hammer mass is 5 cm in diameter at 4.5 kg and is dropped from a set height
of 45 cm. The weight of the guide tube and metre is
approximatley 2 kg. The Australian shipping case weighs approximatley 7 kg. The
total weight is around 14 kg. Instrument height is 70 cm and the
guide tube is 15 cm in diameter. The shipping case is around 22
cm by 25 cm by 80 cm. The output at the fourth drop of the standard Clegg Hammer when dropped from
its standard height is known as the Clegg Impact Value (CIV), where the output is in Clegg units, i.e. where 1 Clegg unit equals 10 gravity units with the resulting decimal fraction truncated. Shown above left is a black-painted mild steel drop-hammer (e.g. Model 883) and shown above right is a stainless steel drop-hammer (e.g. Model GTM-SS-E), both with hardened steel ends.